This invention relates to an improved process for preparing 1-aryl-2-benzimidazolinones. These compounds, methods for their preparation, and their utility as insecticides are known. Rosnati, Gazz. Chim. Ital., 86, 275 (1956) and Oftedahl et al., J. Org. Chem., 28, 578 (1963) both teach the preparation of 1-aryl-2-benzimidazolinones by reacting a carbanilide with aqueous hypochlorite ion. While this process is effective to produce benzimidazolinones, the yields from this process are generally unsatisfactory.